Piston ring



5M. OSBORNE.

PISTON RING.

APPLICATION FILED APR-27,1921.

1,421,295. Patented June 27, 1922.

gwuen roz saras raranr oases.

FBANIK'M. OSBORNE, 0E ANAOONDA, MONTANA.

PISTON RING.

Specification of Letters Patent. Patented June 27, 1-922.

I Application filed April 27, 1921. Serial No. 464,781.

and other types for insuring a pressure tight bearing against the surface of the cylinder wall, and more especially to provide a one-- piece s lit ring-of even weight or thickness throng out as distinguished from those rings now in common use which are of a variable or graduated thickness from the extremitiestoward an intermediate point; and with this object in view the invention consists in a construction and combination of parts of which a preferred embodiment is shown in the accompanying drawings,

1 wherein Figure 1 is a plan view of a piston ring embodying the invention applied in the operative position to a piston, the latter being shown in section.

' Figure 2 is a side view of the same showing the preferred form of joint.

igure 3 is a transverse sectional view thereof.

The ring proper as shown at 10 is of the,

\ single piece split ring type preferably having a step; lap joint 11 between its extrem-,

ities, the ring being of uniform gauge or of even-thickness and width through but with a cross sectionally V-shaped or grooved inner surface as indicated at 12, and in co-operative .supplementally expansive relation with the body portion of the ring is a steel Wire expander 13 also of ring form but of sinuous contour providing a series of oppositely directed arches of which the bases bear respectively against the inner surface of the ring'and the bottom of the ring groove 14 in the piston 15. The crowns or apexes of thearches ofthe expander bear in the annular angle formed by the cross section'- ally V-shaped seat in the inner surface of the-body portion of the ring so as to maintain a uniform relative position and prevent lateral displacement of theexpander,

.and by reason of the uniform expansive effect of the expander the body portion'of the ring is held uniformly or with a uniform pressure against the surface of the cylinder wall without necessitating as in the ordinary practice the thickening of the ring from its extremities or joint toward a point diametricall opposite to the joint.

aving described the invention, what is claimed as new and useful is A device for the purpose indicated consisting of a split ring having overlapping extremities, and a spring expander formed with alternate oppositely .directed arches for hearing contact against the opposed surfaces of the body portion of the ring bottom and the ring roove of a piston, the s ring being of materially reduced width wit respect to the ring and the latter being providedwith a seat'on its inner periphery consisting of a cross sectionall V-shaped groove in which the apexes of t 1e arches engage to preclude lateral displacement of theexpander and maintain a uniform relative position of the same.

In testimony whereof he afilxes his signature. v

. FRANK M. osB'oRNE. 

